Study of the Factors Influencing Structure and Properties in Aluminium and Aluminium Alloy Strip

Abstract

The structure and properties of continuously cast, grain refined commercial purity aluminium and aluminium 1.25% manganese alloy, have been studied during the production of strip for deep drawing applications. Hot rolling textures were found to be dependent upon alloying content of the material, pre-treatment and hot rolling reduction. Compression testing indicated that hot rolling temperature is of significance in the control of hot rolling textures. During subsequent cold rolling intensification of deformation textures occurred and the final texture was found to depend upon the cold rolling work roll diameter, cold rolling reduction, hot rolled texture, and alloy. Cold rolling with 76.2 mm diameter rolls caused intensification of the pure metal texture in the centre of strip and the rotation of the hot rolled surface texture. However, cold rolling with 762 mm diameter rolls caused a lesser intensification of the pure metal texture in the strip centre and the retention of the hot rolled surface texture. Subsequent annealing textures were found to depend upon the annealing treatment, cold rolling work roll diameter, alloy and prior cold rolling reduction. The annealed strips were found to display planar and normal anisotropy to an extent dependent upon the production process variables from the hot rolling stage to the final annealing stage. An analysis of the relationship between the structure and properties of the finally annealed strip showed that production control is necessary, from the beginning of the hot rolling stage to the final annealing stage, in order to produce strip of good deep drawability.